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Get Started Free →Prompt engineering standards and context engineering principles for AI agents based on Anthropic best practices. Covers clarity, structure, progressive discovery, and optimization for signal-to-noise ratio.
.claude/skills/aiskillstore-prompting/SKILL.md| Test case | Without → With | Effect | Δ tokens | Δ turns |
|---|---|---|---|---|
| case-01 | ✗→✓ | ▲ Improved | 21% | 0% |
| case-02 | ✓→✓ | = Same ✓ | -15% | 0% |
| case-03 | ✓→✓ | = Same ✓ | -48% | 0% |
| case-04 | ✓→✓ | = Same ✓ | 3% | 0% |
| case-05 | ✓→✓ | = Same ✓ | 67% | 0% |
Context engineering = Curating optimal set of tokens during LLM inference
Primary Goal: Find smallest possible set of high-signal tokens that maximize desired outcomes
Use clear semantic sections:
✅ Good: "Validate input before processing" ❌ Bad: "You should always make sure to validate..."
✅ Good: "Use calculate_tax tool with amount and jurisdiction" ❌ Bad: "You might want to consider using..."
✅ Good: Bulleted constraints ❌ Bad: Paragraph of requirements
Don't load full data dumps - use references and load when needed
Persist important info outside context window
Delegate subtasks to specialized agents with minimal context
❌ Verbose explanations ❌ Historical context dumping ❌ Overlapping tool definitions ❌ Premature information loading ❌ Vague instructions ("might", "could", "should")
For full standards: read ${PAI_DIR}/skills/prompting/CLAUDE.md
Anthropic's "Effective Context Engineering for AI Agents"
| Case | Status | Duration (ms) | Turns | Tokens | Tool calls | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Without | With | Δ | Without | With | Δ | Without | With | Δ | Without | With | Δ | ||
case-01 | fail→pass | 4,417 | 2,227 | -50% | 1 | 1 | 0% | 750 | 910 | +21% | 0 | 0 | — |
case-02 | pass→pass | 15,778 | 10,257 | -35% | 1 | 1 | 0% | 2,746 | 2,339 | -15% | 0 | 0 | — |
case-03 | pass→pass | 12,083 | 3,214 | -73% | 1 | 1 | 0% | 2,151 | 1,113 | -48% | 0 | 0 | — |
case-04 | pass→pass | 12,838 | 10,545 | -18% | 1 | 1 | 0% | 2,182 | 2,258 | +3% | 0 | 0 | — |
case-05 | pass→pass | 4,633 | 3,566 | -23% | 1 | 1 | 0% | 674 | 1,124 | +67% | 0 | 0 | — |
case-06 | pass→pass | 14,825 | 11,273 | -24% | 1 | 1 | 0% | 2,357 | 2,356 | -0% | 0 | 0 | — |
case-07 | pass→pass | 9,527 | 5,449 | -43% | 1 | 1 | 0% | 1,610 | 1,441 | -10% | 0 | 0 | — |
case-08 | pass→pass | 8,176 | 5,443 | -33% | 1 | 1 | 0% | 1,254 | 1,404 | +12% | 0 | 0 | — |
case-09 | pass→pass | 11,579 | 9,892 | -15% | 1 | 1 | 0% | 2,152 | 2,186 | +2% | 0 | 0 | — |
case-10 | pass→pass | 16,668 | 9,198 | -45% | 1 | 1 | 0% | 2,546 | 2,008 | -21% | 0 | 0 | — |
case-11 | pass→pass | 9,704 | 5,848 | -40% | 1 | 1 | 0% | 1,518 | 1,485 | -2% | 0 | 0 | — |
case-12 | pass→pass | 15,961 | 10,594 | -34% | 1 | 1 | 0% | 2,596 | 2,275 | -12% | 0 | 0 | — |
case-13 | pass→pass | 3,353 | 2,707 | -19% | 1 | 1 | 0% | 581 | 984 | +69% | 0 | 0 | — |
case-14 | pass→pass | 14,634 | 7,711 | -47% | 1 | 1 | 0% | 2,306 | 1,754 | -24% | 0 | 0 | — |
case-15 | pass→pass | 17,531 | 10,749 | -39% | 1 | 1 | 0% | 2,943 | 2,340 | -20% | 0 | 0 | — |
case-16 | pass→pass | 10,529 | 6,555 | -38% | 1 | 1 | 0% | 1,700 | 1,696 | -0% | 0 | 0 | — |
case-17 | pass→pass | 8,322 | 2,521 | -70% | 1 | 1 | 0% | 1,324 | 907 | -31% | 0 | 0 | — |
case-18 | pass→pass | 11,543 | 8,667 | -25% | 1 | 1 | 0% | 1,932 | 1,920 | -1% | 0 | 0 | — |
case-19 | pass→pass | 12,909 | 9,131 | -29% | 1 | 1 | 0% | 1,899 | 1,946 | +2% | 0 | 0 | — |
case-20 | pass→pass | 15,915 | 9,816 | -38% | 1 | 1 | 0% | 3,088 | 2,308 | -25% | 0 | 0 | — |
case-21 | pass→pass | 11,606 | 6,473 | -44% | 1 | 1 | 0% | 2,202 | 1,695 | -23% | 0 | 0 | — |
case-22 | pass→pass | 8,401 | 6,063 | -28% | 1 | 1 | 0% | 1,666 | 1,667 | +0% | 0 | 0 | — |
DecimalAI ran this skill against gemini-3.6-flash twice over the same eval suite — once with the skill loaded and once without — and compared the two runs case by case. 22 cases were attempted. The headline lift of +5 percentage points is the difference between those two pass rates over the 22 comparable cases.
Without the skill loaded, the model failed this case. With it loaded, the same prompt on the same model passed. This is one improved case from the latest verified run; every case, including any that regressed, is in the table above.
Other measured skills in the registry, with their headline benchmark lift.